Salt Water Threatens Rivers
By RANDOLPH E. SCHMID
04:17 PM ET 08/19/99
WASHINGTON (AP) - Salty seawater is creeping upstream in some Eastern rivers,
potentially threatening municipal water supplies as the drought continues. Reduced
streamflow in rivers such as the Delaware and Hudson is allowing the encroachment, the
U.S. Geological Survey reports. On the Hudson River, the salt front is about five
miles downstream from the water intakes for the city of Poughkeepsie, north of New York
City, the Survey said.
``Right now, it's standing still and water which is being pumped into the Hudson
from area reservoirs is keeping the salt front at bay,'' Survey hydrologist Ward Freeman
said in a statement. But, he added, the salt front may begin moving upstream again
and only significant rainfall will wash out the threat. ``It's serious because
Poughkeepsie relies on freshwater from the Hudson. They don't have any groundwater
resources they can draw from,'' he said.
When Poughkeepsie faced a similar problem during the drought of 1995 water was
released from the Sacandaga Reservoir to block further saltwater movement.
The Delaware River, which feeds much of the Philadelphia region's water supply,
is also being monitored for saltwater encroachment.
Currently, the salt front is near the Philadelphia International Airport, 20
miles downstream from the city's water intakes. But that's 11 to 12 miles upriver of where
it normally is in summer. ``We have to keep the salt front downstream from the mouth
of the Schuylkill River,'' said hydrologist Tony Navoy. ``There are a series of reservoirs
up the Delaware River and into New York and we have to tap into those to keep the river
flows high enough to keep the salt at bay.''
Navoy said a well field near Pennsauken, N.J., which serves much of suburban
Trenton, could be affected if the salt front moves further upriver.
If groundwater levels in that well field fall below mean sea level and river
water is salty, the salt can contaminate the underground water.
In addition to its bad taste, salt water can be a serious health hazard for
people on salt-restricted diets. Salt causes the human body to retain water, making the
heart work harder and increasing blood pressure. Salt water can also corrode underwater
equipment and cause freshwater organisms to move or die off.
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